Create a custom filter in AngularJS

In this video we will discuss how to create a custom filter in AngularJS.

Custom filter in AngularJS1. Is a function that returns a function2. Use the filter function to create a custom filter

Let us understand creating custom filter with an example.

Script.js : In the example below we are using the filter function to create a custom filter that converts integer values 1, 2, 3 to Male, Female and Not disclosed respectively. gender is the name of the filter. With in the filter function we have an anonymous function that returns another anonymous function. The input parameter for the inner anonynous function is the gender integer value. The switch statement in the function returns the corresponding string value.

var app = angular

.module("myModule", [])

.filter("gender", function () {

returnfunction (gender) {

switch (gender) {

case 1:

return"Male";

case 2:

return"Female";

case 3:

return"Not disclosed";

}

}

})

.controller("myController",
function
($scope) {

var employees = [

{ name: "Ben",
gender: 1, salary: 55000 },

{ name: "Sara",
gender: 2, salary: 68000 },

{ name: "Mark",
gender: 1, salary: 57000 },

{ name: "Pam",
gender: 2, salary: 53000 },

{ name: "Todd",
gender: 3, salary: 60000 }

];

$scope.employees = employees;

});

HtmlPage1.html : In the view, we use the custom gender filter like any other angular built-in filter with a pipe character.

<!DOCTYPEhtml>

<htmlxmlns="http://www.w3.org/1999/xhtml">

<head>

<title></title>

<scriptsrc="Scripts/angular.min.js"></script>

<scriptsrc="Scripts/Script.js"></script>

<linkhref="Styles.css"rel="stylesheet"/>

</head>

<bodyng-app="myModule">

<divng-controller="myController">

<table>

<thead>

<tr>

<th>Name</th>

<th>Gender</th>

<th>Salary</th>

</tr>

</thead>

<tbody>

<trng-repeat="employee in
employees">

<td>{{employee.name}}</td>

<td>{{employee.gender|gender}}</td>

<td>{{employee.salary}}</td>

</tr>

</tbody>

</table>

</div>

</body>

</html>

In the above example we have the custom filter in Script.js file. In a real world application you may the custom filters in a separate script file (Filters.js for example). To do this reference the module object and use the filter function.

Filter.js : The custom filter is moved to a separate file

///
<reference path="Script.js" />

app.filter("gender", function () {

returnfunction (gender) {

switch (gender) {

case 1:

return"Male";

case 2:

return"Female";

case 3:

return"Not disclosed";

}

}

});

Script.js : After moving the filter function to a separate Filters.js file, the Script.js file will now look as shown below.

///
<reference path="angular.min.js" />

var app = angular

.module("myModule", [])

.controller("myController",
function
($scope) {

var employees = [

{ name: "Ben",
gender: 1, salary: 55000 },

{ name: "Sara",
gender: 2, salary: 68000 },

{ name: "Mark",
gender: 1, salary: 57000 },

{ name: "Pam",
gender: 2, salary: 53000 },

{ name: "Todd",
gender: 3, salary: 60000 }

];

$scope.employees = employees;

});

HtmlPage1.html : The only change required in the view is to reference the Filters.js file